A cool and light dessert is a perfect finale to a summer supper, especially when the scale betrays no great indiscretion the next morning.

Fresh fruit is the sensible ending when the summer crops fill the produce stands. What could be nicer than a plate of assorted melons or of sliced papaya and pineapple, sprinkled with lemon or lime juice, freshly grated ginger, chopped mint or shredded coconut?

Or, if you are of the pudding or parfait persuasion, fresh fruit combined with dairy products and honey add a nice elegance to the evening. Even the dieter can't have too much grief over the following recipes-- especially the first one. STRAWBERRY PARFAIT (6 to 8 servings) 2 packages unflavored gelatin 1/2 cup cold water 2 tablespoons lime juice 3 cups fresh strawberries, washed and culled 1 quart buttermilk 1/3 cup honey 6 large, fresh, strawberries for garnish

Combine gelatin with juice over low heat and stir until gelatin dissolves and mixture is clear. Put in blender with raspberries and puree. Blend in honey to taste. Beat cream stiff and fold into berry mixture.Pour into dessert dishes and chill firm. Garnish with mint sprigs.